Clamshell cartons are widely used for serving fast food in high-volume outlets in North America as well as in many parts of the world. These cartons provide a sturdy means to temporarily store hamburgers and sandwiches between the time these meals are served and the moment the cartons are opened to retrieve the meals. Most recognizably, clamshell cartons are used by both McDonalds of Oakbrook, Ill. and Burger King of Miami, Fla. to contain the iconic Big Mac™ and Whopper™ hamburgers.
As is a common practice among many consumers of fast food, the clamshell carton serves not only as a means to transport its contents, but as a convenient serving container replacing the need for a plate or other dish upon which to rest the sandwich/hamburger between bites. Practically, however, the clamshell container was not designed primarily as a serving container, but rather as a means to protect and prevent disassembly of a hamburger while it is being transported. As can be appreciated, to assist in maintaining the hamburger's integrity, the hamburger usually occupies almost the entirety of a designated clamshell container's volume with the edges of the burger often coming in contact with the opposing walls of the container.
Accordingly, when the container is opened and a cover portion is flipped away from a tray portion along a common living hinge, access to the hamburger is limited. When reaching to retrieve the meal, there is very little space for consumer to insert his/her fingers and grab the burger. Consumers must work their fingers around the sides of the sandwiches, rubbing the outside of their fingers alongside the inner walls of the carton in order to reach below the meal in an effort to grab and then lift the sandwich. This is an awkward and inconvenient process.
The problem is exacerbated when the consumer uses the container as a serving tray and, accordingly, repeatedly re-inserts and removes the sandwich from the tray. In addition, consumers must lower their meals carefully so that they are placed inside the tray in a flat, resting position. This requires extra focus or concentration. If the hamburgers are not carefully lowered inside the walls of the carton, spillage of the burger contents may result. For example, if a hamburger is being re-inserted into a carton and part of the burger is placed on the lower carton's wall, the hamburger will lie at an angle. As a result, some of the hamburger contents may slide or spill out.
As a general point of reference, folds (or fold lines) are illustrated in the figures as dashed lines; whereas, folds including perforations are shown in dotted lines.